Field of the Invention Including Description of the Prior Art
This invention relates generally to a web handling apparatus, and more particularly to such an apparatus having tractor pins for feeding the web into marginal edge slitters and a web chopper for chopping the web at its marginal edge so as to effect a chopped feed hole band separated into short strips.
It is customary for continuous paper webs to have marginal feed holes along one or both marginal edges thereof to facilitate pin feeding of the web through a printer. After leaving the printer, the marginal feed holes are usually trimmed from the web before manifolding so that the customer will ultimately receive the paper product minus the punched feed holes. Trimming may be carried out on an apparatus having a pair of rotary slitters for slitting the web just inwardly of the feed holes as the web is fed into the slitters by a tractor pin feed device which engages the feed holes. Such a feed device is typically shown in U.S. Pat. No. 3,606,122 to Brewster et al and commonly owned herewith. The disclosure of such patent is specifically incorporated herein by reference in its entirety.
The feed band separated from the web at the marginal edge or edges thereof by the slitters is normally dropped into a waste receptacle in continuous form after which it is bundled or otherwise handled. These continuous feed tapes may be chopped up before bundling although this operation has been generally avoided because it is too costly and time consuming.
It has been found that, by chopping up the continuous tapes into lengths of approximately 41/2 inches, several times the amount of chopped feed tapes can be collected in a single waste container as compared to the unchopped and continuous feed tapes. The savings in storage space and labor costs in handling the waste material can therefore be quite substantial if the feed tapes are chopped before being collected.
An apparatus for trimming the sides of sheets and chopping the scraps thereby formed is disclosed in U.S. Pat. No. 2,133,595 to Thomas. A pair of slitters are used for the trim operation and trim choppers are disposed downstream thereof. Endless belts in engagement with opposite sides of the side trim are provided for guiding the side trim into the choppers.
In U.S. Pat. No. 3,110,208 to Mitchell, Jr. et al and in U.S. Pat. No. 2,970,329 to Fitzgerald, devices are disclosed for trimming metal strips and shoe leather strips wherein slitting knives and chopping knives are disposed on a common belt.
In each of the aforementioned patents chopping means are not disclosed in combination with a continuous paper web trimming apparatus using a tractor pin feed device for supporting the web already chopped in the vicinity of its punched hole feed bands and for feeding the web toward rotary slitting knives. In Thomas endless belts are disposed between the slitting knives and the chopping knives to insure that the trim strips do not buckle or jam or otherwise get out of line before reaching the chopping knives. In both Fitzgerald and Mitchell, Jr., et al, the chopping and slitting operations take place simultaneously and are not separated as in the present invention with a tractor pin feed device lying therebetween.